BERLIN – Pornography has been elevated to an art form as never before at the Berlin Film Festival, which has spotlighted the industry and its commercial success.

After the leading actress in last year’s festival-winning film was hounded to tears by German tabloids when it emerged she had a history in hard-core, the Berlinale turned the controversy on its head by making porn a centerpiece this year.

Several films focusing on sexual repression, especially in the United States, have drawn large and appreciative audiences in Berlin, one of the world’s top festivals with a liberal tradition in a city governed by a popular gay mayor.

And not only is the topic a critical hit. Porn, driven by pay-television, the internet and DVDs, boasts annual revenues of over $10 billion, equal to Hollywood’s mainstream output.

Journalists, film buyers and the public crowded into a theater Sunday to see a documentary, “Inside Deep Throat,” about a history-making 1972 U.S. film featuring what has been described as “extreme fellatio” that made porn mainstream.

“Deep Throat” was one of the most commercially successful films ever, grossing a estimated $600 million after costing $25,000 to make. In 2002, 11,000 porn films were made, the documentary says, compared with less than 500 Hollywood films.

There are other Berlin films on sex, including an explicit documentary looking at gay porn in Los Angeles and the sad lives of former porn stars. There is also a competition drama about Alfred Kinsey, the pioneering U.S. sex researcher.

Young filmmakers attending the festival’s “Talent Campus” were treated to an unusual seminar Sunday entitled “Directing Sex.” French director Catherine Breillat gave a lecture on “ways of directing intimacy for the screen.”

Berlinale director Dieter Kosslick, who like most Germans is not bothered by “Head-On” actress Sibel Kekilli’s earlier porn career, said examining sexual repression was not a special tribute to the German woman of Turkish origin.

“It’s always good to talk about sex — and to see it on the screen,” Kosslick told Reuters. “‘Kinsey’ is about an enlightened man in sexually repressed America. ‘Inside Deep Throat’ shows what a business the film was and how people were ruined by it.”

The documentary “Inside Deep Throat,” which cost $1 million to make, was one of the most coveted tickets at the festival.

Journalists and buyers lined up for hours for a seat to its late night screening yet there were still inelegant battles at the entrance as the crowd rushed forward when the doors opened.

The documentary tracks the efforts of U.S. President Richard Nixon’s government to ban “Deep Throat” on grounds it violated obscenity laws. It ended up making the film more popular and sparked a long debate on freedom of expression.

The film spawned the phrase “Deep Throat,” used not only by comedians but also by journalists as the name of a high level source they relied on for their Watergate investigation — which ultimately led to Nixon’s resignation.

“We thought we were making a film about 1972 but as we were making it we realized it was also a film about the present,” said co-director Randy Barbato after the screening.

“Sex came out of the closet for a while but it’s back in the closet now,” added co-director Fenton Bailey. “Americans are still very uncomfortable about sex. Even though it is everywhere it’s also nowhere. America is sexually dysfunctional.”

Barbato said American conservatives tended to speak more about “moral values” and against pornography in public, but demand and sales of porn was highest in conservative states.

“There’s so much hypocrisy,” he said.

With a 1970s pop music soundtrack, “Inside Deep Throat” includes graphic scenes from the original with its 23-year-old star Linda Lovelace performing her unusual technique on Harry Reems, who plays a wacky doctor.

He was later convicted for conspiracy to transport obscenity across state lines.

Before “Deep Throat,” which was made by a hairdresser named Gerard Damiano, pornographic films were usually limited to short 10-minute “loops” seen in clubs or backrooms of book stores.

“Deep Throat” was an hour and included a plot. Screened first in New York, its popularity spread amid attempts to ban it.